The transmission system operator does not meter power produced from decentralised solar pv which is connected directly to regional distribution networks, and has effectively removed around 900MW of demand from the grid over the last year.
As a result National Grid estimates that this summer will see peak demand reach just 37.5GW, as solar pv capacity increased by 2GW in 2014.
The lowest predicted demand level is set to be around 18.6 GW, in line with the lows predicted for summer last year.
“It is likely that embedded solar generation will lead to a permanent reduction in summer peak demands,” its outlook report said.
But in a blog published alongside the report National Grid’s head of energy strategy and policy Roisin Quinn said that even though their control room would not be concerned with maintaining supply margins, as is the case in winter, the summer season “can be just as challenging”.
“It’s just the nature of the challenge that changes,” Quinn said.
From an electricity point of view balancing demand with supply can be difficult in the summer due to less predictable demand patterns created by human behaviour.
“Although we don’t have a World Cup or a Royal Wedding this summer, another Andy Murray final at Wimbledon or a big soap storyline might mean we’re put on standby to dispatch power to meet any pick-up in demand,” Quinn said.
National Grid’s director of market operations Cordi O’Hara said balancing gas flows could also come with difficulties due to shifting market patterns in both gas supply and generation fuel sources.
“The complexity of operating the gas network is increasing, with two main issues: We have an increase in the variety of supply sources and it’s not easy to predict where the gas will be coming from. We also have gas and electricity interactions, with gas fired power generation currently marginal plant, and a growing amount of intermittent electricity generation adding to the unpredictability of flows,” O’ Hara said.
The National Grid report highlighted variations in LNG, gas storage injections and European interconnection as the key factors leading to “greater operational unpredictability”.
Utility Week has previously reported that the UK’s LNG imports tripled in the first quarter of the year compared with Q1 2014 as the global market shifts away from declining prices in the Asian region.
Since 2011 global LNG producers have favoured the price premium in the Asian gas markets. But as Asian prices fall due to low demand and plummeting oil prices, the UK has fast become an increasingly attractive destination for cargoes.
In addition, while gas flows from domestic sources are expected to be steady on last year, flows from continental Europe may be lower than last year due to production restrictions at the Groningen field in the Netherlands, the report said.